Cathleen Black loves a challenge. These days, the president of I Hearst Magazines is launching three books almost simultaneously. The third issue of Tina Brown's Talk magazine has just hit the stands. CosmoGIRL!, Cosmopolitan's little sister, is being test marketed, and Oprah's magazine is due out in the spring."Oh, I love what I'm doing," laughs Black, "but I think I must have … [Read more...] about The 100 Most Influential Irish Americans in Business: The Queen of Hearst